Die set leader bearings with variable clearance



Sept. 22, 1953 K. JANISZEWSKI DIE SET LEADER BEARINGS WITH VARIABLE CLEARANCE Filed Aug. 30, 1948 w a a} A m ATTORNEY! Patented Sept. 22, 1953 OFFICE pm SET LEADER BEARINGS WITH VARIABLE CLEARANCE Kasimir Janiszewski, Milwaukee, Wis. Application August 30, 1948, Serial No. 46,903 18 Claims. (01. 164-118) This invention relatesto die set leader bearings with variable clearance.

A punch and die require mounting in such a manner that they may be operated with the greatest of accuracy. The punch and the die are ordinarily mounted upon upper and lower plates known as punch carrier and die shoe respectively. These plates are usually guided for vertical reciprocation by means of leader pins mounted on the shoe and bushings slidable on the leader pins andmounted in the punch carrier. Because of the high degree of accuracy required to assure proper co-action of the punch with the die it has been customary to make the leader pin and bushing with an extremely close fit. This has made somewhat diflicult the problem of assembling the punch and die and it has also resulted in a rather stiff action. Many times the punch and die can be separated only by the exercise of power; a press considerable power has been required to operate the press in'both directions due to the tight fit of the bushing on the leader pin to assure the desired accuracy.

The present invention has for its object the provision of a'leader pin and bushing assembly which conforms to the highest standards of accuracy only at the precise moment when the accuracy is needed-that is to say, at the moment when the punch and die commence to act upon the work, there being considerablefreedom of movement between the leader pin and the bushing at all other points in the stroke of-the press.

Other objects of the invention and the manner in which theyare achieved willbe more apparent from the following disclosure of the invention.

In the drawings:

Figure 1 is a view in plan of a die set embodying the invention, portions of the punch carrier being broken away to expose the means for varying the clearance between the parts automatically in the operation thereof.

Figure 2 is a view taken in section on the line 2-2 of Fig. 1.

Figure 3 is a fragmentary detail view on an enlarged scale similar to a portion of Fig. 1.

Figure 4 is a fragmentary detail view in transverse section on an enlargedscale-on the line 4 4 of Fig. 3.

Figure 5 is a view in plan, partially broken away to a horizontal section, showing a modified embodiment of the invention. Figure 6 is a view similar to Fig. 5 showing a further modified embodiment of the invention.

Figure 7 is a vie taken in section on the line 1"1ofFig."6.

Even during normal use in upper end of a leader pin,

Figures 1 and 2 show an assembly comprising a punch carrier 8, a shoe 9, a punch l0, and a die I l, the punch carrier and punch being guided for movement respecting the die and the shoe by means of a leader pin 12 mounted in the shoe, and a bushing I 3 carried by the punch carrier. In accordance with conventional practice, two leader pins and bushings are employed. They are identical and consequently the description of one will serve to disclose the structure of both. I

The leader pin i2 is driven into an openingin the shoe 9 to fit therein as tightly as possible. No play is provided between the leader pin andthe shoe. Similarly the bushing l3 has a driven fit in the punch carrier 8. The present construction deviates from standard practice, however, in the fact that between the bushing l3 and the leader pin I2 considerable clearance is provided so that there is a very free running fit between these parts. Means is provided, however, to assure that at th moment of interaction of the punch and the die upon the work piece [4, the fit is suddenly tightened to assure the greatest accuracy at the only time when accuracy is required. v

To this end the leader pin I2 is provided with a longitudinal channel at l5. In this channel there is an inserted strip H; which can conveniently be held by a set screw I! threaded into the shoe 9 and engaging the insert. For the greater part of its length the back side of the insert is rectilinear to fit closely to the back of the channel IS in the leader pin. However, at a predetermined point, which isusually near the the back side of the insert [6 is cut away as indicated at l8 in Fig. 2 to provide a certain amount of resilience. Directly opposite the point where the insert is relieved, its outer face is shouldered at 19 and in the shoulder is fitted a cam button 20 which may be welded in place or otherwise securely fixed to the insert "3 as a part thereof. The button 20 is preferably made of the hardest available material.

At a correspondingpoint the bushing I3 is provided with a transverse bore 2! opening into the bearing through which the leader pin slides; In this bore I insert a plunger or rod 22 having weldcomprising the rod or cylinder 22 and the hardened button 23- at the end thereof is positionedby means of a set screw 24 threaded into the outer wall of the punch carrier plate 8 in registry with the opening 2| of thebushing so that the set screw acting against the plunger and button unit 22, 23, may position such unit where, upon engagement of button 23 with the cam button 20, all of the clearance between the leader I2 and the bushing l3 will be fully taken up, the bushing and leader pin being thereupon abruptly forced into intimate contact. Since the button 20 is mounted on the insert I6 and since the vertical position of the letter i re a ivel as d u tabl b le e ing the set screw I1, it will be evident that the point at which the clearance between the leader pin and the bushing is taken up can be accurately fixed with reference to the point where accuracy is required due to the engagement of the punch with the work piece I4.

As best shown in Fig. 2, the margins 9f the cam and cam follower 20, 23, are slightly rounded so that these two buttons contact each other only momentarily, thus limiting the tight fit between the leader pin and the bushing solely to the instant of engagement of the punchand die. At ,all other times, the bearing is very free -sufnciently so to offerlittle or no resistance to the sliding movement of the carrier respecting shoe 3. in the construction shown in Figures 3 and l the leader pin I20 is likewise free throughout most of its range of movement in the bushing I The insert, [69, instead of having a hardened button welded to it, is outwardly bowed at 20B to provide a cam surface. The space behind the outwardly bowed portion of the insert is indicated at H in Fig 4 and provides resilience for the purposes above described. The outwardly bowed cam 200 co-acts with a cam follower which comprises a wheel or disk 2 rotatably mounted upon anti-friction bearings as shown in Fig, 1 to rotate upon the guidepin Zfi which @Zitdlldfi inwardly of the plate 80' from the rear thereof. A slot at -2 l in the bushing affords access of the cam follower disk 25 to the earn 230. The dish turns in a slot 28 provided in the punch carrier plate 89 and the space around the disk is enclosed by filling the slot with an insert 2 9 held in place by cap screws 33, 34. The operation is exactly in accordance with the operation of the device of Figures 1 and 2. There is ample clearancebetween the leader pin and the bush-ing for perfectly free reciprocable movement of the punch carrier ex,- cept at the very instant when accuracy is desired. At-that instant the cam 2B3 engages the pa n follower roller '25 to take up all clearance and assure, at that point alone, an extremely tight fit between the leader pin and the bushing for the purpose of assuring accuracy of registration of the punch and die.

-e 5- h he s h ppl eet eh 9 t e invention to a leader pin of triangular cross section of the general type disclosed in r ny applicaticn Serial No 672,053 entitled pie gets" and filedMay ;24, 1946, now Patent No. 2 ,6' ll l 3 5 The bushing comprises a pair of hardened metal plates I3-I, set at an angle into a bess 32 at the side of the punch carrier plate ill. The ,outside bearing s a e e t e n ula leade pin is provided by a P a e e e e es t9 t e bees b b ew The e ter ie e 9 the leader p m s han e at 1 e ,ihehher aheve e i-h dhe i e t I!" ee eepehde i general to the insert Is shown in Fig. '32 it similarly provided with a hardened button at (II which co-a cts with a relatively f xed hard button 2 3i carried by a rod or'plunger 22 tioned by set screw 24I, screw threaded int cap 33.

Figures 6 and 7 suggest the application 9f the cam roller principle-to a triangular leader pin ee e construction. The leader pin I22 is reciprocable in angular bearing surfaces formed, in this instance, directly in the boss 322 of the carrier plate 82. As in the construction of Fig. 5, the outer side of the bearing is closed by a cap 332 anchored by cap screws 34, 35. The roller 252 may conveniently be mounted with or without ent i eh h hea in 901 e P1 435 d p in a Plu The pl rreri es wi h a h at 38 to fix it in a counterbore in a suitable opening bered from the inner face of the cap 332. The diameter of the roller 252 is such that at the cted point where accuracy is required, the roller rides on to the cam surface formed by the oatward euryature at 202 of the insert I62 of the leader pin I22.

I claim:

1, a die set comprising a punch carrier member having a punch mounted thereon and a i member fe l a i u i hi ifim for coaction with the punch requiring accuracy of relat e pe i eh the t e f hi ei i the Wo k a .i a P heh esp t e ea ned 113 1 5 31 en hhihei en o guide m ehe is i qih s .eehri and ehee m mb r .e e laive xe iprae tieh and e mrri a ,leecler in e he ie'd be of eei memb rs an bas in ther of said members, said e h eted 7 lea er pin and bus bein meeh ne a ro: id fre i i fit hrehshe lt th re te ra e of ii e e et h 9 the 591 een iihe $1. Plz l m eem fil fol we mea s mounted 0K .3 3 uid m n a P$ $i9 g@ 1 solely in .a a ge of mqvement including the point o e reeti b w n t e rea h and d e sai n and cam follower acting laterally upon the leader pin and bushing to tighten the bearing engagement vtherebetv'veen in said range to steady the punch carrier plate at said point.

2. In .a ,die set comprising a die and punch and he e t y e rreeehl Pl te 441 .92; ich th di n n e at ree ee reh he hte r nte action, the combination with a relatively recipro, ehl le d Fi -Q 5 1??? and a b shin memb 'i heeti e r eeh t o a d Pl t and m l ed te rr-eris e hea ns s r ce endin ela ive iree lehi meremex -thrershoi t er ate an e e -ve eeimi eh said m m ers e a arn 1 ieet h la era ly m th h arin hr eee 'i'h'e b as m mb r and e we ol.-

t er mzei eiihe "la eral from t e ea n e face of the other and positioned for engagement a the el and 2 9 1 appizeaeh th i e in e ac ion sa d e meh t em ollow vin i ted -eetieh in h d ee ieh lat of he path o relative movement between said members, whereby t9 tighten said members in bearing engagemer t vupgn each other adiacent the predeterined rel .t thei ran o elat v re pro aeh "WE the d e a d p n int r- 3. In a die set comprising .a vdie and punch and 'telreeieheea le late po w ch he die and punch are respectively mounted for inter- WfiQh. th QI bm P P with .3 b and a de pm respe t ve co ne t ai plates. said leader pin being relatively reciprocable freely through said bushing, of a cam button connected with the bushing, a second cam button connected with the leader pin, the cam button of the bushing being mounted for projection into the bore of the bushing and the cam buttcn pf the leader P b i ehiweml nrei et ha t e respect e t ns ein q aon e e see t D x mentsubst antially limited to a point t ceurse of relative reciprocation of the leader pin and bushing where the die and punch interact.

4. In a die set comprising a die and punch and relatively reciprocable plates upon which the die and punch are respectively mounted for interaction, the combination with a leader pin and tubular bearing means respectively connected to said members, said pin being reciprocable through said tubular bearing means, of a cam connected with the leader pin, a cam follower within the tube of the bearing means, and a support of limited resilience between the leader pin and said cam, said cam and cam follower being positioned for coaction in the range of movement of the plates where the die and punch interact,

5. In a die set comprising a die and punch and relatively reciprocable plates upon which the die and punch are respectively mounted for interaction, the combination with a leader pin member and a tubular bearing member in which the leader pin is relatively movable, said members being respectively connected to said plates, of laterally engageable cam and cam follower ele ments structurally associated with the respective members and disposed for engagement with each other in the zone in which the die and punch interact in the course of such movement, the said members having bearing surfaces free for relative movement throughout the greater part of a predetermined range of movement and adapted to be tightened upon the engagement of said elements at the said point in such range where the punch interacts with the die.

6. The device of claim 5 in which one of said elements is provided with an adjustable support mounting it upon one of said members,

7. The device of claim 5 in which one of said elements is provided with a relatively yieldable support longitudinally adjustable upon one of said members.

8. The device of claim 5 in which one of said members is longitudinally slotted and provided with an insert longitudinally adjustable in said slot and upon which one of said elements is mounted.

9. The device of claim 5 in which one of said members is longitudinally slotted and provided with an insert longitudinally adjustable in said slot and upon which one of said elements is mounted, the said insert having a concave recess between it and the member on which it is mounted at the point at which said element is carried by said insert.

10. The device of claim 5 in which said elements comprise a pair of hardened metal buttons.

11. The device of claim 5 in which one of said elements comprises a roller mounted for rotation on engagement of the other element therewith.

12. In a die set comprising punch and shoe plates having a punch and die respectively mounted thereon for action upon intervening work, the combination with leader :pin and bushing members connected with the respective plates and having bearing surfaces machined for relatively free reciprocation, of cam and cam follower elements mounted upon the respective members in positions for mutual engagement at a predetermined point in the range of such reciprocation where the punch acts on the work to take up the play between the leader pin and bushing members to steady the punch plate at that point, said cam and cam follower being elsewhere out of engagement whereby to permit play between said members.

13. The device of claim 12 in which the leader pin member is longitudinally slotted and provided with an insert adjustable in said slot and upon which one of said elements is mounted.

14. The device of claim 12 in which the bushing member is provided with a transverse bore and a plunger positioned in said bore and upon which one of said elements is mounted, the punch plate being provided with a set screw acting upon said plunger for the positioning thereof in said bore.

15. The combination with a punch carrier plate and a shoe plate having a punch and die respectively mounted thereon for action on intervening work, of a leader pin connected to one of said plates, the other plate being provided with bearing means in which said leader pin is freely reciprocable, a roller mounted on said last mentioned plate, and cam means carried by the leader pin and so positioned as to coact with said roller at the point in the course of leader pin reciprocation in the bearing means where said die and punch act on the work to take up play between the leader pin and said bearing means at said point.

16. The combination set forth in claim 15in which the leader pin is channeled and provided with an insert formed outwardly to provide said cam means and to constitute a resilient support therefor.

17. The combination set forth in claim 15 in which the leader pin is longitudinally channeled and provided with an insert adjustable in said slot and formed outwardly to provide said cam means and to constitute a resilient support therefor, together with means for fixing the adjustment of said insert respecting said leader pin whereby the point of interaction of the cam means and roller is adjustable.

18. The combination set forth in claim 15 in which said roller is mounted in a plug and the bearing means of said plate comprises a cap having a recess in which said plug is positioned.

KASIMIR J ANISZEWSKI.

References Cited in the file of this patent UNITED STATES PATENTS 

